Increase bone integrity in laying hens

A strong skeleton is important for animal welfare and laying performance

Background on the challenge

Each egg contains about 2g of calcium (Ca) in the form of calcium carbonate (CaCO3). The Ca needed to form the eggshell is coming from feed (60 – 75 %) and the bone (40 – 25 %). Ca from the bone is mobilized preferentially from the medullary, but also trabecular bone. The latter gives strength to the bone and cannot be repaired after Ca has been mobilized, which reduces bone strength and increases the risk for brittle bones. This leads to osteoporosis and increases the risk for fractures, for example in the keel bone.

Therefore, it is important to maximize Ca stores during rearing and minimise Ca mobilization from bone during laying. Another important factor is vitamin D3, which is a key player in Ca-metabolism. Vitamin D3 is needed not only to absorb Ca from the gut but also in concert with e.g. PTH to mobilize and restore Ca in bone, and to form the eggshell.

The implication for the industry

Keel bone damage (KBD), which includes keel bone deformations and keel bone fractures, has been reported to affect up to > 90 % of all birds in alternative housing systems, and the incidence depends on age and breed. KBD is a concern for animal welfare and reduces performance (

KBD is a multifactorial problem that needs to be addressed from different angles, especially because it increases with age, thus causing the hens to be kept longer every year. One was to achieve skeletal integrity is to provide sufficient Ca, supporting the vitamin D3 metabolism throughout the life of the laying hen.

  • fast time to action

  • improves Ca-metabolism

  • increases bone strength

Panbonis® is a complementary feed that contains a standardized level of 1,25 dihydroxycholecalciferol-glycosides (1,25(OH)2D3-gly) from dried and ground Solanum glaucophyllum leaves. 1,25(OH)2D3-gly can only be absorbed after the sugar molecule is released from 1,25(OH)2D3 by specific enzymes that are present in the intestine. This is a gradual process, ensuring a slow release of the bioactive component. Once it is absorbed, it does not need additional activation steps, like vitamin D3 or 25-hydroxycholecalciferol (25(OH)D3) do, which means that Panbonis® can directly support the animal even in periods when specific activation enzymes in liver and kidney are limited.

Supplementing a commercial layer diet with 100g/t of Panbonis supports the Ca-metabolism of the hen and helps to maintain a healthy skeleton.

  • Supports the crucial role of vitamin D3

  • 100% Natural

  • GMO-free

  • Standardized content of the active ingredient

  • Gradually absorbed from the intestine

  • Considered a complementary feed in the EU

  • High processing and storage stability

Mode of action

Vitamin D3 needs to conversion steps to become metabolically active. The first step happens in the liver, where vitamin D3 is converted to 25-hydroxycholecalciferol (25(OH)D3). 25(OH)D3 is the storage form of vitamin D3 and gives a good indication of the vitamin D3 status of the animal. The second activation step happens in the kidney, where the 25(OH)D3 is converted into 1,25-dihydroxycholecalciferol (1,25(OH)2D3). 1,25(OH)2D3 then interacts with the vitamin D3 receptor (VDR), which is – among others – located in the gut cells. There 1,25(OH)2D3 increases the expression of Calbindin, a Ca-binding protein in the cell that transports the Ca from the gut to the blood. When providing Panbonis, which naturally contains 1,25(OH)2D3-gly, only the glycosides need to be cleaved by endogenous enzymes, and the free 1,25(OH)2D3 can be absorbed and is directly available at the site of Ca-absorption.

Poultry – Vitamin D Metabolism

Trial results

Significant linear interaction between vitamin D3 and 1,25(OH)2D3 on tibia breaking strength and tibia weight at oviposition in laying hens aged 65 – 75 weeks of age (adapted from Frost et al., 1990)

  Vitamin D3: 1500 IU    
1,25(OH)2D3 (ug/kg) 0 0,5 1,0
Tibia breaking strenght (kg) 7,29 7,92 8,05
Tibia Weight 6,20 6,31 6,55
Our solution Panbonis®
  • fast time to action
  • improves Ca-metabolism
  • increases bone strength